Overall assessment system of combined mammography and ultrasound for breast cancer screening in Japan

Mammography is the only screening method with evidence in support of reduced breast cancer mortality, but yields poor accuracy outcomes in women with dense breast tissue. The Japan Strategic Anti-cancer Randomized Trial (J-START) was conducted as part of the measures implemented to deal with women with dense breast tissue. Although the sensitivity was increased, the specificity was significantly lower in the intervention group because further examination was required in all positive cases classified by either mammography or ultrasound in the J-START. To address the issue, an overall assessment system of combined mammography and adjunctive ultrasound for breast cancer screening has been developed in Japan. The basic concept is based on a comprehensive assessment that includes a mammography assessment followed by an adjunctive assessment for ultrasound similar to the clinical setting. Currently, mammography alone is recommended for population-based breast cancer screening in Japan, but additional ultrasonography is extensively available for women, especially for women with dense breasts with shared decision-making for personalized breast cancer screening. The overall assessment system is recommended for use in Japan when breast cancer screening is conducted using both mammography and ultrasonography. In this article, we summarize the advantages of the overall assessment and the simultaneous mammography/ultrasound method, the basic approach used in Japan to assign the overall assessment category for breast cancer screening, and we outline the future directions of adjunctive screening ultrasound.

Breast cancer screening using digital breast tomosynthesis compared to digital mammography alone for Japanese women

BACKGROUND

The purpose of this study is to confirm the position of DBT in breast cancer screening in Japan, to assess cancer detection rates, recall rates, positive predictive value (PPV), and to evaluate the type of mammographic findings of cancer with the use of digital mammography alone (2DDM) and combined with digital breast tomosynthesis (DBT).

METHODS

11,894 examinations of the opportunistic breast cancer screening using only 2DDM and 2DDM plus DBT were performed from May 1, 2017 to March 31, 2019. The 11,894 women [3535 women who received DBT in addition to 2DDM (3D group) and 8359 who received 2DDM only (2D group)] participated in this study. The study was approved by the Institute's Ethics Committee and all participants provided written informed consent.

RESULTS

The recall rate was 2.6% for the 3D group and 3.6% for the 2D group (p < 0.01). The cancer detection rate was 0.17% in both 3D and 2D groups (p = 0.978). The positive predictive value (PPV) was 6.5% for the 3D group and 4.7% for the 2D group (p = 0.484). The cause of the decrease in recall rate was due to a decrease in the finding of focal asymmetric density (FAD).

CONCLUSION

The recall rate was improved by using DBT for breast cancer screening in Japanese women. Cancer detection rates were exactly the same in DBT and 2DDM groups, so only DBT non-inferiority could be verified. We have verified that breast cancer screening combined with DBT is useful even for Japanese women to reduce unnecessary further examination.

A deep learning-based automated diagnostic system for classifying mammographic lesions

BACKGROUND

Screening mammography has led to reduced breast cancer-specific mortality and is recommended worldwide. However, the resultant doctors' workload of reading mammographic scans needs to be addressed. Although computer-aided detection (CAD) systems have been developed to support readers, the findings are conflicting regarding whether traditional CAD systems improve reading performance. Rapid progress in the artificial intelligence (AI) field has led to the advent of newer CAD systems using deep learning-based algorithms which have the potential to reach human performance levels. Those systems, however, have been developed using mammography images mainly from women in western countries. Because Asian women characteristically have higher-density breasts, it is uncertain whether those AI systems can apply to Japanese women. In this study, we will construct a deep learning-based CAD system trained using mammography images from a large number of Japanese women with high quality reading.

METHODS

We will collect digital mammography images taken for screening or diagnostic purposes at multiple institutions in Japan. A total of 15,000 images, consisting of 5000 images with breast cancer and 10,000 images with benign lesions, will be collected. At least 1000 images of normal breasts will also be collected for use as reference data. With these data, we will construct a deep learning-based AI system to detect breast cancer on mammograms. The primary endpoint will be the sensitivity and specificity of the AI system with the test image set.

DISCUSSION

When the ability of AI reading is shown to be on a par with that of human reading, images of normal breasts or benign lesions that do not have to be read by a human can be selected by AI beforehand. Our AI might work well in Asian women who have similar breast density, size, and shape to those of Japanese women.

TRIAL REGISTRATION

UMIN, trial number UMIN000039009. Registered 26 December 2019, https://www.umin.ac.jp/ctr/.

Characteristics of ultrasonographic images of ductal carcinoma in situ with abnormalities of the ducts

Purpose

Although the number of ductal carcinoma in situ (DCIS) cases has increased with the spread of breast cancer screening in Japan, there are very few reports that summarize ultrasound image features of DCIS. The Japan Association of Breast and Thyroid Sonology (JABTS) investigated the incidence of DCIS with masses and non-mass abnormalities and the characteristics of US images in a retrospective, multicenter, observational study (JABTS BC-02 study). The purpose of this report is to clarify the proportion of DCIS with abnormalities of the ducts with each ultrasound finding and the characteristics of US images.

Methods

The JABTS BC-02 study population was comprised of patients who were examined by ultrasonography, underwent surgery, and were histopathologically diagnosed with DCIS at each study site between January 2008 and December 2012. The US images of DCIS and pathology and clinical information were retrospectively collected from 16 institutions in Japan. The US images were evaluated by 22 experts on the Central Image Interpretation Committee of JABTS.

Results

Abnormalities of the ducts were noted in 78 (10.5%) of 705 US images of DCIS. Of the 78 cases, the distribution of abnormalities of the ducts was focal or segmental. The second characteristic was the presence of internal echoes in dilated ducts. All cases were accompanied by intraductal solid echoes, and 40 cases (51.3%) were accompanied by echogenic foci. In addition, intraductal solid echoes were continuous or multiple in 72 cases (92.4%), and the shape of the solid echoes was broad-based and/or irregular in 62 cases (79.5%).

Conclusion

DCIS cases with duct abnormalities on ultrasound were investigated in this study. The important characteristics were as follows: (1) the distribution of ductal dilatation was focal or segmental, (2) solid parts were present in the dilated ducts, (3) the distribution of internal echoes was continuous or multiple, (4) the shape of solid echoes was broad-based and/or irregular, and (5) internal echoes were sometimes accompanied by echogenic foci. Accurate evaluation of these findings may be useful for diagnosing DCIS. Although the duct abnormalities are included in “ASSOCIATED FEATURES” in ACR BI-RADS ATLAS (USA), we emphasize that this concept is very important for understanding US characteristics of DCIS.

Multicenter Prospective Study of Color Doppler Ultrasound for Breast Masses: Utility of Our Color Doppler Method

The use of color Doppler ultrasound (CD) for distinguishing between benign and malignant breast lesions remains controversial. This study (JABTS BC-04 study) was aimed at confirming the usefulness of our CD diagnostic criteria. We evaluated ultrasound images of 1408 solid breast masses from 16 institutions in Japan (malignant: 839, benign: 569). Multivariate analysis indicated that vascularity (amount of blood flow), vascular flow pattern ("surrounding marginal flow" or "penetrating flow") and the incident angle of penetrating flow were significant findings for distinguishing between benign and malignant lesions. However, the sensitivity and specificity of B-mode alone did not improve significantly with CD addition (97.6% → 97.9%, 38.3% → 41.5%, respectively). We explored the causes of these negative results and found that age should have been considered when evaluating vascularity. Simulation experiments suggested that specificity is significantly improved when age is taken into consideration (38.3% → 46.0%, p < 0.001) and we thereby improved our diagnostic criteria.

The Loss of Lymph Node Metastases After Neoadjuvant Chemotherapy in Patients With Cytology-proven Axillary Node-positive Primary Breast Cancer

BACKGROUND

Axillary lymph node (LN) dissection after neoadjuvant chemotherapy (NAC) still remains a standard treatment of initially LN-positive primary breast cancer because of the difficulty of assessment of LN status. The aim of this study was to assess the LN status after NAC in initially LN-positive primary breast cancer patients who were assessed as clinically LN-negative after NAC (ycN0) and identify factors associated with loss of LN metastasis.

PATIENTS AND METHODS

The study cohort comprised 279 patients with cytology-proven LN-positivity before NAC. LN status was assessed by ultrasonography. Regional recurrence-free survival and overall survival according to pathologic LN after NAC (ypN) status were assessed in patients with ycN0.

RESULTS

Of the 279 patients, 179 patients (64.2%) had ycN0. High nuclear grade, estrogen receptor-negative (ER^-), and human epidermal growth factor receptor 2-positive (HER2⁺), were significant predictors of ycN0/ypN0 (P < .001, .007, and .046, respectively). Metastases persisted in 1 or 2 LNs for 5 (20.0%) of 25 patients with ER^-/HER2⁺ and for 4 (21.1%) of 19 patients with ER^-/HER2^-, and in 3 or more LNs for 0 (0%) of 25 patients with ER^-/HER2⁺ and for 1 (5.3%) of 19 patients with ER^-/HER2^-. Patients with ER⁺ tumors had more numerous residual LN metastases than those with ER^- tumors (P < .001). Among patients with ycN0, ypN status was not associated with regional recurrence-free survival or overall survival.

CONCLUSIONS

Three or more residual LN metastases were rare in patients with ER^- tumors if assessed as ycN0 by ultrasonography. Prospective studies are needed to confirm the prognostic impact of not performing axillary lymph node dissection in such patients.

Abstract P2-14-17: Long-term oncologic safety of nipple-sparing mastectomy with immediate reconstruction

Background

Nipple-sparing mastectomy (NSM) is an alternative procedure to skin-sparing mastectomy (SSM) for selected patients who undergo immediate reconstruction. However, the evidence of long-term oncologic safety of NSM has not been established. In this study, we aimed to compare the prognosis of breast cancer patients who underwent NSM to those who underwent SSM with immediate reconstruction.

Methods

The clinicopathological factors including recurrence site, pathologic stage, nipple-tumor distance, histological type, lymphovascular invasion, margin status, ER, PgR and HER2 status of stage 0–III primary breast cancer patients who underwent NSM or SSM with immediate primary reconstruction with tissue expander from our breast center database was retrospectively assessed. Patients with a nipple tumor distance of &lt;1 cm who underwent NSM were excluded. 190 patients who underwent NSM and 729 patients who underwent SSM were included in the analysis. All patients underwent MRI or US before treatment. Nipple-tumor distance was mainly measured by MRI.

Results

The median follow-up period was 71 months (range: 10 - 131 months) for the NSM group and 79 months (range: 9 - 140 months) for the SSM group. There were no significant difference of clinicopathological factors between the NSM group and the SSM group, except of the larger diameter of tumor in the SSM group. NSM was performed for 60 patients (32%) with stage 0, 71 patients (37%) with stage I, and 59 patients (31%) with stage II/III. SSM was performed for 185 patients (26%) with stage 0, 268 patients (37%) with stage I, and 276 patients (37%) with stage II/III. Local recurrence was found in 11 (5.8%) patients in the NSM group and in 44 (6.0%) patients in the SSM group. In the NSM group, only one (0.5%) patient had local recurrence in the nipple areola complex. In terms of DFS and overall survival (OS) rate, there was no difference between the NSM group and the SSM group (DFS; 89.5% vs 89.2%, HR, 1.044; p = 0.8992; 95% CI, 0.5116–1.9519, and OS; 98.4% vs 96.4%, HR, 0.963; p = 0.9116; 95% CI, 0.473–1.793). According to breast cancer subtype, in the NSM group, all of the 11 patients (100%) who developed local recurrence in the NSM group was hormone receptor (HR)-positive/HER2-negative breast cancer. 29 of the 44 patients (65.9%) who developed local recurrence in the SSM group was HR-positive/HER2-negative, 6 patients (13.6%) was HR-negative/HER2-positive, and 7 patients (15.9%) was triple-negative breast cancer. Among patients who had received neoadjuvant chemotherapy, the NSM group (3 of 14 patients, 21.4%) had a trend for higher local recurrence rate than the SSM group 7 of 116 patients (6.0%) (p = 0.0813). However, no local recurrence in the nipple areola complex was observed for the NSM group. In addition, there was no difference of OS between the NSM group (92.9%) and the SSM group (90.5%) (HR, 0.903; p = 0.9943; 95% CI, 0.049-4.739).

Conclusions

Our results suggested that NSM with immediate reconstruction might be safe as well as SSM for breast cancer with the nipple–tumor distance of &gt;1 cm with respect to their prognosis and local control regardless of breast cancer subtype or invasiveness. Further studies with a large sample size to assess the risk of local recurrence for NSM after neoadjuvant chemotherapy.

Citation Format: Yamashita Y, Hayashi N, Nagura N, Kajiura Y, Yoshida A, Takei J, Suzuki K, Tsunoda H, Yamauchi H. Long-term oncologic safety of nipple-sparing mastectomy with immediate reconstruction [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-17.

Abstract P5-18-05: Clinicopathological characteristics and prognosis of young patients with ductal carcinoma in situ

Background: The peak age at diagnosis of breast cancer differs between patients in Asian countries (40 - 50 years), and those in Western countries (60 - 70 years). With the increasing use of screening mammography, the incidence of ductal carcinoma in situ (DCIS) has increased significantly in younger Asian women. Nevertheless, our knowledge of the clinicopathological features and prognosis in young patients with DCIS is relatively limited. We aimed to compare the clinicopathological features of younger patients with that of older patients with DCIS and to evaluate their prognostic factors.Methods: A total of 1445 women were diagnosed with DCIS between the years 2005 and 2015. Patients with the past history of breast cancer and managed without surgery were excluded. The young age group included patients &lt;50 years of age, whereas the old age group included patients ≥50 years of age at diagnosis. We compared the clinicopathological characteristics [tumor size, surgery type, estrogen receptor (ER) and progesterone receptor (PgR) status, HER2 status, nuclear grade, margin status, radiotherapy, endocrine therapy, family history of breast cancer, and screening presentation or presentation with symptoms] and prognosis [disease-free survival (DFS), and overall survival (OS)] between the groups. DFS included the following events: contralateral breast cancer, loco-regional, and distant recurrences. DFS and OS were estimated using the Kaplan–Maier method. The risk factors associated with events were estimated using the log-rank test for univariate analysis. P values &lt; 0.05 were considered statistically significant.Result: Among the 1445 patients diagnosed with DCIS, 1281 were included in this study. The median age at diagnosis was 47 years (range, 22-87 years). The median follow-up time was 72 months (range, 1-162 months). ER and/or PgR status was positive in 1133 patients (88%). HER2 status was positive in 289 patients (23%). Premenopausal status was noted in 867 patients (68%). The median tumor size was 3.0 cm. Of 1281, 202 (18%) patients received endocrine therapy, 846 (66%) received breast conserving surgery, and 724 (86%) received radiation therapy. There were 765 patients (60%) in the young group. Significantly more patients in the young group had low nuclear grades, were ER and/or PgR positive, were HER2 receptor negative, underwent mastectomy, presented with symptoms, and had close/positive margins. Fifty-eight (4.5%) events occurred: 41 (3.2%) contralateral breast cancers, 19 (1.5%) loco-regional recurrences, and one (0.1%) distant metastasis. No death due to breast cancer was reported. On multivariate analysis, the young group (hazard ratio: 2.24, 95% CI: 1.01 - 4.95, P = 0.04), and presentation with clinical symptoms (hazard ratio: 2.09, 95% CI: 1.07-4.10, P = 0.03) significantly correlated with worse DFS. OS was not significantly different between the groups.Conclusion: This was the largest study with young patients with DCIS in the Asian population. We found that age at diagnosis was a significant independent factor associated with DFS. While genetic background also requires consideration, women with DCIS at &lt;50 year of age may require intensive surveillance. This result requires confirmation with longer follow-up.

Citation Format: Seki A, Matsuda N, Kajiura Y, Kobayashi D, Hayashi N, Tsunoda H, Suzuki K, Yoshida A, Takei J, Yamauchi H. Clinicopathological characteristics and prognosis of young patients with ductal carcinoma in situ [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-05.

Magnetic Resonance Imaging Combined With Second-look Ultrasonography in Predicting Pathologic Complete Response After Neoadjuvant Chemotherapy in Primary Breast Cancer Patients

BACKGROUND

Magnetic resonance imaging (MRI) or ultrasonography (US) alone is limited in the ability to predict the pathologic complete response (pCR) accurately after neoadjuvant chemotherapy (NAC). The aim of the present study was to predict the pCR using MRI combined with second-look US in primary breast cancer patients.

MATERIALS AND METHODS

A total of 1274 consecutive primary breast cancer patients who were examined by MRI and second-look US before and after NAC and had undergone breast-conserving surgery from 2004 to 2014 were included. The positive predictive value (PPV) of a clinical complete response (cCR) by MRI alone and MRI plus US was assessed. A CR was defined as no residual invasive carcinoma. The presence of a residual in situ component was also assessed (ypTis).

RESULTS

Of the 1274 patients, 333 (26.1%) had a pCR (ypT0/is), and 102 (8.0%) had a residual in situ component (ypTis). A cCR was found in 247 patients (19.4%) using MRI alone and in 182 patients (14.3%) using MRI plus US. The PPV for a cCR using MRI alone was 79.4% and the PPV for MRI plus US was 86.8%. The PPV for a cCR by MRI plus US was the greatest at 98.1% in the estrogen receptor-negative (ER^-)/human epidermal growth factor receptor-positive (HER2⁺) group (86.5% in the ER⁺/HER2⁺, 83.0% in the ER^-/HER2^-, and 64.7% in the ER⁺/HER2^- groups). The PPV for residual in situ component was as low as 72.2%.

CONCLUSION

Our results have shown that MRI combined with second-look US in predicting for a pCR was useful compared with MRI alone, especially for ER^-/HER2⁺. However, it was difficult to predict for the presence of a residual in situ component. Our ongoing prospective multi-institutional study has shown that adding vacuum-assisted biopsy to MRI plus second-look US is warranted to improve the prediction of pCR for omitting breast surgery.

Ductal Carcinoma in situ of the breast in sclerosing adenosis encapsulated by a hamartoma: A case report

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Ductal Carcinoma in situ in sclerosing adenosis encapsulated by a hamartoma is rare.

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The diagnosis is difficult due to the appearance of these combined lesions.

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Atypical appearance of a hamartoma may suggest a co-existing malignancy.

Introduction

Ductal Carcinoma in situ (DCIS) of the breast can develop in areas of sclerosing adenosis. The radiographic finding of sclerosing adenosis is a spiculated mass and can look like invasive ductal carcinoma. We report a patient with DCIS in sclerosing adenosis encapsulated by a hamartoma, with imaging findings quite different from the typical findings of sclerosing adenosis.

Presentation of case

A 73-year old woman, with no previous mammography, presented with a palpable mass in the left breast. Mammography showed a 36 mm well-defined mass with fat density in the middle outer quadrant of the left breast. Ultrasonography showed a well-defined mass in the same area which was composed of hypoechoic and hyperechoic areas. The histological diagnosis by core needle biopsy was sclerosing adenosis. We considered the patient’s age and tumor size and performed a partial mastectomy for both diagnosis and treatment. Final pathology showed DCIS in sclerosing adenosis in a hamartoma.

Discussion

This patient had DCIS in an area of sclerosing adenosis, encapsulated by a hamartoma. DCIS can develop in areas of sclerosing adenosis, and can appear similar to invasive ductal carcinoma, so we must avoid misdiagnosis or over-treatment. Malignant transformation of a hamartoma is rare, but can occur since it contains epithelial tissue. Definitive biopsy should be performed due to the possibility of a malignancy inside the hamartoma.

Conclusions

When diagnosing a hamartoma, the presence of atypical findings on imaging studies, should suggest the possibility of malignancy. Although rare, a malignant tumor may be present inside the hamartoma.

Abstract P3-01-03: The loss of lymph node metastasis after neoadjuvant chemotherapy in patients with cytologically proven node-positive primary breast cancer

Purpose:While the sensitivity to neoadjuvant chemotherapy (NAC) depends on breast cancer subtype, it has been reported that over 30% of patients with node-positive breast cancer achieved an axillary pathologic complete response (pCR) after NAC. However, axillary lymph node dissection (ALND) still remains as a standard treatment because of the difficulty of assessment of lymph node (LN) status after NAC. ALND will be omitted if axillary LN status is accurately assessed. Our purpose of this study was to predict the loss of axillary LN metastasis after NAC in primary breast cancer patients.

Patients and Methods: Among 997 consecutive patients who underwent surgery after NAC from January 2006, to December 2016, 279 patients with cytologically proven node-positive were included in this analysis. All patients were assessed using CT or PET-CT, and ultrasonography (US) before NAC. LN status after NAC was assessed by US. Patients with cT4 tumor, and supra/subclavicular and parasternal LN metastasis were excluded. Clinical LN status after NAC (ycN) was compared to pathological LN status (ypN) on surgical specimen. The association between LN status and clinicopathological factors including nuclear grade (NG), tumor size, the use of trastuzumab, and breast cancer subtypes, was assessed.

Result: Of the 279 patients with LN-positive before NAC, 166 patients (59.5%) had ER+/HER2- tumor, 51 patients (18.3%) had ER+/HER2+ tumor, 33 patients (11.8%) had ER-/HER2- tumor, and 29 patients (10.4%) had ER-/HER2+ tumor. 179 patients (64.2%) had ycN0 and 102 patients (36.6%)had ypN0. There was significant difference of rate of the loss of LN metastasis after NAC; 37 of 166 patients (22.3%) with ER+/HER2- tumor, 24 of 51 patients (47.1%) with ER+HER2+ tumor, 19 of 33 patients (57.6%) with ER-HER2- tumor, and 22 of 29 patients (75.9%) with ER-HER2+ tumor, (p&lt;0.01).The accuracy of assessment of the loss of LN metastasis by US (ycN0/ypN0) was high in 20 of 25 patients (80.0%) with ER-/HER2+ tumor and in 14 of 19 patients (73.4%) ER-/HER2- tumor compared to ER+ tumor; 21 of 39 patients (53.8%) with ER+/HER2+ tumor and 34 of 96 patients (35.4%) with ER+/HER2- tumor (p&lt;0.01). For patients with ycN0/ypN+, the median number of residual LN metastasis was 1 in ER-/HER2+ tumor (range:1-2) and ER-/HER2- tumor (range:1-3), and 2 in ER+/HER2+ tumor (range:1-6) and ER+/HER2- tumor (range:1-14). Among patients with ER-/HER2+ tumor, there was association between the loss of LN metastasis and the use of trastuzumab (p&lt;0.01). There was no association between the loss of LN metastasis and NG or tumor size.

Conclusion: Our results showed patients with ER-/HER2+ tumor and cytologically proven LN metastasis who received NAC with trastuzumab might have the loss of LN metastasis if assessed as ycN0 by US after NAC, whereas, the patients in ER+ tumor have a high risk to have residual LN metastases after NAC even if assessed as ycN0. Further studies are warranted the prognostic impact of the omission of ALND for these populations.

Citation Format: Namura M, Hayashi N, Tsunoda H, Yoshida A, Takei J, Suzuki K, Nakamura S, Yamauchi H. The loss of lymph node metastasis after neoadjuvant chemotherapy in patients with cytologically proven node-positive primary breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-03.

Discrepancies Between Pathological Tumor Responses and Estimations of Complete Response by Magnetic Resonance Imaging After Neoadjuvant Chemotherapy Differ by Breast Cancer Subtype

INTRODUCTION

The influence of breast cancer (BC) subtype in discrepancies between pathologic complete response (pCR) and complete response by magnetic resonance imaging (MRI-CR) after neoadjuvant chemotherapy (NAC) have not been discussed well. We evaluated the association between BC subtype and pCR or only residual in situ lesion without invasive cancer (pCR/in situ⁺) in patients with MRI-CR (positive predictive value [PPV]).

MATERIAL AND METHODS

From the data of 716 patients with primary BC who were diagnosed with invasive cancer and treated with NAC and then surgery from January 2009 to May 2014 at St. Luke's International Hospital, 180 patients were determined to have MRI-CR by retrospective chart review. BC subtypes at baseline were classified into 6 subtypes, as strong estrogen receptor (ER⁺⁺), moderately positive ER (ER⁺), negative ER (ER^-), and HER2 status expression.

RESULTS

Three subtypes had PPV (pCR) ≥ 50%: ER^-/HER2⁺ (56.3%, 27/48), ER^-/HER2^- (57.6%, 34/59), and ER⁺/HER2⁺ (56.2%, 9/16). However, PPV (pCR) for the ER⁺⁺/HER2^- and ER⁺⁺/HER2⁺ subtypes was < 30%; notably, only 12.0% (3/25) for the ER⁺⁺/HER2^- subtype, which was significantly low (P < .001) compared with ER⁺⁺/HER2^- and other subtypes. PPV (pCR/in situ⁺) was significantly low at 20.0% in the ER⁺⁺/HER2^- subtype (P < .001 compared with other subtypes). PPV (pCR/in situ⁺) in other subtypes was collectively greater than 60%, and was 91.7% in the ER^-/HER2⁺ subtype.

CONCLUSION

We should interpret carefully MRI-CR of NAC to evaluate residual disease for ER⁺⁺/HER2^- BC.

BMI change and abdominal girth as risk factors of breast cancer

e13082

Background: While obesity is considered the risk factors of breast cancer, Asian women are tends to be lower BMI compared with Western populations and there are not much reports that studied association between obesity and risk of breast cancer in Asian women. In this study, we analyzed the associations of breast cancer incidence and body mass index at age 18-20 (BMI 18-20y), BMI at research entry (BMI at entry), change of the BMI from BMI 18-20y to BMI at entry (BMI change), abdominal girth at research entry (AG), HbA1c [N] at research entry (HbA1c). Methods: We used data of the women who had undergone medical check-ups and opportunistic breast cancer screening at least twice at the Center for Preventive Medicine of St. Luke’s International Hospital between April 1, 2005 and March 31, 2014. Statistical analysis was done by using multivariate Cox proportional hazards model to investigate the hazard ratio (HR) at 95% confidence intervals (95% CI). Results: In this 10 year period, 30,109 women (20,043 women were premenopausal and 10,066 women were postmenopausal women) received opportunistic breast cancer screening at least twice. After analysis of 131656.6 person-years follow up during 10 years, 325 initial breast cancer cases were identified 202 cases in premenopausal women, and 123 cases in postmenopausal women. Among postmenopausal women, BMI change and AG were positively associated with breast cancer incidence. Women whose BMI change were major gain group (> +5.0) were significantly likely to develop breast cancer compared with stable group (BMI change were between -2.5 to +2.5) [HR: 1.902 (95% CI = 1.202-3.009)]. Large AG ( > 90cm) was significant risk to develop breast cancer versus less than 70cm [HR: 2.500 (95% CI = 1.091-5.730)]. In the analysis classified BMI18-20y more and less than 20 kg/m2, large BMI18-20y ( > 20 kg/m2) postmenopausal women with high HbA1c ( > 6.5) was more likely to develop breast cancer compared with low HbA1c ( < 5.5) [HR: 3.325(95% CI = 1.307-8.460)]. Conclusions: Increase of BMI after age of 18-20 years and large AG in postmenopausal women have positive association with breast cancer development. High HbA1c women whose BMI18-20y was over 20 kg/m2 are significantly to develop breast cancer.

Ultrasound Image Classification of Ductal Carcinoma In Situ (DCIS) of the Breast: Analysis of 705 DCIS Lesions

The Japan Association of Breast and Thyroid Sonology (JABTS) proposed, in 2003, a conceptual classification system for non-mass abnormalities to be applied in addition to the conventional concept of masses, to facilitate detecting ductal carcinoma in situ (DCIS) lesions. The aim of this study was to confirm the utility of this system and to clarify the distribution of these findings in DCIS lesions. Data on 705 surgically treated DCIS lesions from 16 institutions in Japan were retrospectively reviewed. All 705 DCIS lesions could be classified according to the JABTS classification system. The most frequent findings were hypo-echoic areas in the mammary gland (48.6%), followed by solid masses (28.0%) and duct abnormalities (10.2%) or mixed masses (8.1%). Distortion (1.3%), clustered microcysts (1.4%) and echogenic foci without a hypo-echoic area (2.5%) were uncommon. These results suggest that the concept of non-mass abnormalities is useful in detecting DCIS lesions.

Abstract P2-08-28: Association between rim enhancement on magnetic resonance imaging and response of chemo therapy

Background: Triple-negative breast cancers (TNBC) are defined as tumors that lack expression of estrogen receptor (ER), progesterone receptor (PR), and HER2. TNBC is characterized as a cancer with a high malignancy potential and a poor prognosis. Systemic therapy that is effective in TNBC is only chemotherapy. On magnetic resonance imaging (MRI), rim enhancement was frequently seen in TNBC. It is reported that rim enhancement on MRI may associated with long-term outcome of patients with triple-negative breast cancer and may potentially serve as a prognostic biomarker in these patients. It is not well known about the relationship of rim enhancement on the MRI and treatment effectiveness of TNBC.

Purpose: We investigated the relationship between rim enhancement on MRI and response of chemo therapy and outcome in patients with TNBC.

Methods: MRI findings of 144 consecutive female TNBC patients, who underwent surgery from 2007 to 2012 in our hospital, were retrospectively reviewed. All patients have taken the MRI in our hospital before treatment, and had undergone chemotherapy before or after surgery. Presence of rim enhancement on MRI was assessed. Rim enhancement was defined more pronounced at the periphery of the mass at early phase.

Association of the presence of rim enhancement on MRI and the pathological complete response (pCR) rate in patients who underwent neo adjuvant chemotherapy (NAC) was assessed using two-sided Pearson's Chi squared tests. Disease free survival (DFS) rates were calculated by the Kaplan-Meier method. Univariate analysis was performed using the log rank test. pCR was defined as the disappearance of invasive cancer.

Results: The median age was 51yo (26-82), and the median observation period was 49 months (5-92). Eighty-one patients (56.2%) underwent NAC and 63 patients (43.7%) underwent adjuvant chemotherapy. Twenty-six cases (18.0%) occurred recurrence or distance metastasis. The presence of rim enhancement were observed 68 cases (42.3%), and non-rim enhancement were 66 cases (57.6%). DFS were not significantly different according to the presence of rim enhancement on MRI(P=0.31).

In NAC patients, 28 patients (34.5%) were led to pCR and 53 (63.4%) were non-pCR. The presence of rim enhancement were observed 44 cases (54.3%), and non-rim enhancement were 37 cases (45.6%). In pCR rate, rim enhancement is higher than non-rim enhancement (40.9%, 27.0%, respectivrly). However, the presence of rim enhancement on MRI was not significantly associated with pCR in TNBC patients (p= 0.190).

Table1. Association between rim enhancement and pCR pCR(%)non-PCR (%)P-valuerim enhancement18 (40.9)26 (59.1) non-rim enhancement10 (27.0)27 (72.9)0.19

Conclusion: The presence of rim enhancement on MRI showed high pCR rate. While, it is not a significant predictor of pCR in TNBC patients.

Citation Format: Motonari T, Yoshida A, Tsunoda H, Hayashi N, Yagata H, Yamauti H. Association between rim enhancement on magnetic resonance imaging and response of chemo therapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-28.

Malignant phyllodes tumor metastasized to the right ventricle: a case report

Cardiac metastasis of malignant phyllodes tumor is very rare. We herein report a rare case that developed cardiac metastasis from malignant phyllodes tumor. A 38-year-old woman underwent lumpectomy, and the final pathological findings showed the 5-cm malignant phyllodes tumor partially containing 1 cm of squamous cell carcinoma. Four months after the first surgery, a local recurrence of malignant phyllodes tumor and distant metastases to the bone, lung, pulmonary main trunk, and right ventricle were detected. Mass reduction surgery of cardiac metastasis of the malignant phyllodes tumor was performed to avoid sudden death. In immunohistochemical findings, the tumor was suspected to be originated in myoepithelial cells because of the expression of smooth muscle lineage including α-smooth muscle actin and Calponin1 and highly malignant characteristics showing MIB-1 and p53 highly positive with angiogenesis. Further studies are needed to clarify the effective treatment to these tumors.